Treating and completion system and method of treating a formation

ABSTRACT

A method of treating a formation includes, running a first string having at least one first port into a completion string having a plurality of second ports, flowing treating fluid through the first string, and flowing treating fluid through the at least one first port and through at least one of the plurality of second ports and into the formation

BACKGROUND

Conventional systems for treatment of earth formations, such as acidizing, in downhole industries typically employ coiled tubing. Coiled tubing is run into a borehole and treatment is performed on one zone of the formation at a time. After treatment of a zone is completed the coiled tubing is moved to align with the next zone and the process is repeated until all desired zones have been treated. This process is time consuming because of the serial nature. Additionally, coiled tubing is unable to reach the toe of wells with long horizontal or highly deviated sections. The maximum flow rate through the coiled tubing is limited because of the flow area available. As such, industry is receptive to new systems and methods that alleviate any of the foregoing concerns.

BRIEF DESCRIPTION

Disclosed herein is a method of treating a formation. The method includes, running a first string having at least one first port into a completion string having a plurality of second ports, flowing treating fluid through the first string, and flowing treating fluid through the at least one first port and through at least one of the plurality of second ports and into the formation.

Further disclosed herein is a treatment and completion system. The system includes, a completion string positioned within a borehole in an earth formation, a first string runnable within the completion string, having a plurality of first ports distributed along the first string that are configured to be in fluidic communication with a plurality of second ports along the completion string. The plurality of first ports are independently settable to a different flow restriction, and a plurality of seals distributed along the first string or the completion string are configured to seal to the other of the first string and the completion string to isolate the plurality of first ports from one another such that treating fluid can be pumped through the first string and through the plurality of first ports and through the plurality of second ports to treat a plurality of zones of a formation simultaneously.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 depicts a schematic of a treating system disclosed herein; and

FIG. 2 depicts a schematic of an alternate treating system disclosed herein.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to FIG. 1, an embodiment of a treating system disclosed herein is illustrated at 10. The treating system 10 includes a first string 14 referred to herein is a treating string that is runnable within a completion string 18. The treating string 14 includes a plurality of first ports 22 referred to herein as treating ports that are distributed along the treating string 14. The treating ports 22 are configured to be in fluidic communication with second ports 26 that are distributed along the completion string 18. Each of the plurality of treating ports 22 is independently settable to a different flow restriction level. The ports 22 and 26 can be simply openings of selected sizes and shapes including perforations, slots and round holes, for example. The ports 22 can also include flow control devices that include restrictors such as annular tortuous flow paths like mazes and helical flow paths, for example. They can also include movable portions such as sleeves to alter restriction of flow therethrough including completely closing flow through one or more of the ports 22, 26. A plurality of seals 30 are distributed along the treating string 14 or the completion string 18 and are configured to seal to the completion string 18. Sealing of the seals 30 isolates each of the plurality of treating ports 22 from one another within the completion string 18. Similarly, seals 32, such as packers, for example, sealingly engage between the completion string 18 and a borehole 50 within an earth formation 38 thereby creating separate zones 34 along the borehole 50. The seals 38 may be aligned with the seals 30 to allow an operator to control flow of fluid through specific ports 22 and through specific ports 26 and into the formation 38 simultaneously. The foregoing structure allows for greater control of injection flow rates along the borehole 50 than is permitted with conventional systems.

The treating system 10 allows for customization of flow restriction through each of the treating ports 22 along the treating string 18. These adjustments can be configured to account for various characteristics and differences between the zones 34. These differences can be due to variations in permeability between the different zones 34, for example. They can also be due to where along the completion string 18 (i.e. relative locations along the completion string 18) each of the treating ports 22 will be located. Flow restriction of the treating ports 22 near a heal 42 of the completion string 18 will likely need to be set at a higher flow restriction level than the treating ports 22 near a toe 46 of the completion string 18 to balance flow of treating fluid between the zones 34 near the heal 42 with the zones 34 near the toe 46.

The treating string 14, unlike conventional treating systems that employ coiled tubing, uses sections of pipe that are connected together in an end-to-end fashion. As such, the treating string 14 can be run through a full length of the completion string 18 regardless of how highly deviated the completion string 18 may be, including when the deviated portion of the completion string 18 is completely horizontal.

Additionally, the inner diameter that defines a flow area through the treating string 14 can be significantly larger than conventional coiled tubing treating lines. As such, treating fluids, such as acid for acidizing the formation 38, for example, can be injected at higher flow rates. These higher flow rates can be beneficial when treating fluid needs to be pumped deep into one or more of the zones 34 including those that have low permeability or are far from the heal. The high flow rates possible allow for treating a plurality of the zones 34 simultaneously, up to and including all the zones 34 along the borehole 50.

In addition to the treating ports 22 being independently customized for flow restriction to the specific desired needs of the zones 34 that will be treated via the treating ports 22, the treating ports 22 can work together in pairs with the second ports 26. Knowing specific distinctive features about second ports 26 allows an operator to customize the treating ports 22 to work in concert with the second-ports 26. This is helpful since some or all of the second ports 26 may be simply slotted openings in a base pipe (as in the present embodiment). In a hydrocarbon recovery application, for example, after injecting a treating fluid, the treating string 14 may be left in place during production of hydrocarbons. In this embodiment employing inflow control devices as the ports 22 can allow for more complete emptying of hydrocarbon from all of the zones 34 than would occur without the inflow control devices 22 being present. Additionally, the inflow control devices delay water breakthrough in highly permeable zones 34 that would likely produce water much earlier if the inflow control devices 22 were not present. Alternately the treating string 14 can be removed from the completion string 18 and hydrocarbons produced through the completion string 18 alone. In yet another embodiment a third string (not shown) could be run into the completion string 18 and production carried out through both the completion string 18 and the third string.

In one embodiment of the treating system 10 the flow restriction levels of the treating ports 22 are adjustable after being run into the completion string 18. Control lines 54 in operable communication with actuators 58 at each of the treating ports 22 can adjust the flow restriction of each of the treating ports 22 as desired in real time. This real time adjustment can include completely closing of the treating ports 22 to thereby allow operators to alter flow rates as well as the total amount of treating fluid supplied to the particular zones 34.

Referring to FIG. 2, an alternate embodiment of a treating system disclosed herein is illustrated at 110. The treating system 110 differs from the system 10 in that instead of treating all of the zones 34 simultaneously, only a subset of the full number of the zones 34 is treated at one time. In the embodiment illustrated three of the zones 34 are treated at one time, although any number of the zones 34 could be included in a subset in an alternate embodiment. As illustrated, the first three zones 34 being treated are those nearest the toe 46. After this first treatment is completed a treating string 114 employed within the completion string 18 is moved toward the heal 42 to align three treating ports 122 thereon with the next three second ports 26 and treating fluid is supplied therethrough. This is repeated until all of the zones 34 have been treated.

The system 110 uses just two seals 130, one on either side of the two outer-most treating ports 122. Although embodiments can use one of the seals 130 between any of the treating ports 122 as each application dictates.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. 

What is claimed is:
 1. A method of treating a formation, comprising: running a first string having at least one first port into a completion string having a plurality of second ports; flowing treating fluid through the first string; and flowing treating fluid through the at least one first port and through at least one of the plurality of second ports and into the formation.
 2. The method of treating a formation of claim 1, further comprising fluidically aligning a plurality of the at least one first ports with a plurality of the plurality second ports.
 3. The method of treating a formation of claim 2, further comprising flowing treating fluid through the plurality of the at least one first ports and through the plurality of second ports aligned with the plurality of the at least one first ports simultaneously.
 4. The method of treating a formation of claim 2, further comprising adjusting restriction of the plurality of the at least one first ports prior to running the first string into the completion string.
 5. The method of treating a formation of claim 2, further comprising adjusting restriction of the plurality of the at least one first ports according to treating fluid flow rates desired at locations along a borehole where each of the plurality of the at least one first ports will be positioned during treatment.
 6. The method of treating a formation of claim 5, further comprising increasing flow restriction of one or more of the plurality of the at least one first ports to be located nearer a heal of the borehole in comparison to one or more of the plurality of the at least one first ports to be located nearer to a toe of the borehole.
 7. The method of treating a formation of claim 5, further comprising increasing flow restriction of one or more of the plurality of the at least one first ports to be located nearer a portion of the formation that has high permeability in comparison to one or more of the plurality of the at least one first ports to be located nearer to a portion of the formation that has low permeability.
 8. The method of treating a formation of claim 1, further comprising removing the first string from the completion string.
 9. The method of treating a formation of claim 1, further comprising producing through the at least one of the plurality of second ports in the completion string and through the at least first port in the first string.
 10. The method of treating a formation of claim 1, further comprising sealing portions along the first string to portions along the completion string.
 11. A treatment and completion system, comprising: a completion string positioned within a borehole in an earth formation; a first string runnable within the completion string, having a plurality of first ports distributed along the first string being configured to be in fluidic communication with a plurality of second ports along the completion string, the plurality of first ports being independently settable to a different flow restriction; and a plurality of seals distributed along the first string or the completion string configured to seal to the other of the first string and the completion string to isolate the plurality of first ports from one another such that treating fluid can be pumped through the first string and through the plurality of first ports and through the plurality of second ports to treat a plurality of zones of a formation simultaneously.
 12. The treatment and completion system of claim 11, wherein independent setting of each of the plurality of first ports allows treating fluid flow through each of the plurality of first ports to be customized to match characteristics of the zones that each of the plurality of first ports will be treating.
 13. The treatment and completion system of claim 12, wherein the customization adjusts for differences in permeability between the zones.
 14. The treatment and completion system of claim 12, wherein the customization adjusts for location along a borehole.
 15. The treatment and completion system of claim 12, wherein the first string is runnable to an end of the completion string regardless of how long a highly deviated portion of the borehole is.
 16. The treatment and completion system of claim 11, wherein at least one of the plurality of first ports and plurality of second ports include inflow control devices.
 17. The treatment and completion system of claim 11, wherein the plurality of first ports are configured to complement the plurality of second ports to create a total desired outward flow restriction through aligned pairs of the plurality of first ports and the plurality of second ports.
 18. The treatment and completion system of claim 11, wherein flow restriction through each of the plurality of first ports is adjustable after the first string is run into the completion string.
 19. The treatment and completion system of claim 18, wherein adjustment of the plurality of first ports includes fully closing the plurality of first ports.
 20. The treatment and completion system of claim 18, wherein adjustment of the plurality of first ports is possible in real time.
 21. The treatment and completion system of claim 11, wherein the first string is retrievable from the completion string after injecting a treating fluid and before producing.
 22. The treatment and completion system of claim 21, wherein a second string is runnable within the completion string prior to production.
 23. The treatment and completion system of claim 11, wherein the first string can be remain in the completion string during production.
 24. The treatment and completion system of claim 11, further comprising a plurality of seals sealingly engaged with both the completion string and the borehole. 